When passing through a doorway, where the door is hinged to the frame on one side and has a latch handle mechanism, for example, on the other side to keep it closed, a pedestrian tends to divert from a straight line direction of travel after unlatching the door and moving it off center. When the door swings away from the individual, he tends to veer off to the side rather than pushing the door fully open to be able to stay on a straight-line path. In the case when the door swings toward the person, he must back-step and then circle around the side of the door. Certainly, extra steps are required, but usually these steps are taken without a moment's hesitation or any extra effort.
This is not the normal procedure for a wheelchair-bound person, though. In the case where a door opens toward an individual in a wheelchair, that person must first maneuver up to the door in order to reach and unlatch the handle. Now that the handle is unlatched, the person must keep a grasp on the handle while backing the wheelchair away from the doorway in order to sufficiently swing the door open wide enough to pass the wheelchair through. Backing away from the doorway in a manual, i.e. nonpowered, wheelchair causes an asymmetric force on the wheelchair due to the use of one arm. Since a person's reach in a wheelchair is approximately at the location of their footrests, the opened door will always tend to "hug" the chair, thus limiting space to maneuver in.
When the door must be opened away from a person in a wheelchair, the task can be equally as difficult. Again, the first step is for the individual to maneuver up to the door to unlatch the handle. Now they must simultaneously push the door open while maneuvering the wheelchair through the door. For one thing, as the door opens, the corner of the wheelchair closest to the hinged edge of the door will be repeatedly blocked by the door until the door is fully opened. Also, as the door opens, the latch edge moves out of reach of the individual thus requiring more and more "stretch" to make the reach or that the person must push on the door nearer and nearer to the hinged edge. Pushing near the hinged edge or stile of the door requires a significantly greater force than pushing on the latch edge or stile due to the shorter moment arm. And, again, whenever the person is in a manual wheelchair, he or she must operate the wheelchair with one arm, again putting an asymmetric load on the operation, something which requires correction for the wheelchair to move along a desired path through the doorway.
For the wheelchair-bound person, the solution would be a device that not only assists in unlatching the door, but also allows the user to maintain a relatively straight pathway through the doorway. It would allow the user to minimize unbalanced loads on the wheelchair while simultaneously minimizing the movement of the wheelchair while it is worked through the doorway.